static pointer pointer_traits::pointer_to(see below r);
static pointer pointer_traits<T*>::pointer_to(see below r) noexcept;
Remark: if element_type is (possibly cv-qualified) void, the type of r is unspecified; otherwise, it is element_type&.
Returns: The first member function returns a dereferenceable pointer to r obtained by calling Ptr::pointer_to(r); an instantiation of this function is ill-formed if Ptr does not have a matching pointer_to static member function. The second member function returns std::addressof(r).